Bimba PCS - Manual (Page 24)

www.bimba.com Technical Assistance: 800-44-BIMBA 24
Troubleshooting
The following information is helpful if you experience difficulties setting up your Pneu-
matic Control System. A problem may be associated with one or a combination of causes,
including a malfunction of your Main Control (PLC), system adjustments, application
parameters, or system inputs (air supply, electrical power, command signal, etc.).
Try the following suggestions to isolate and solve the problem. If the problem persists or
cannot be rectified, contact your local distributor or our Technical Assistance Center at
800-44-BIMBA. Our website (www.bimba.com) contains the latest information
regarding product updates, so it may be helpful to check there for the latest product
support information.
The Actuator Does Not Move
Problem:
Solution: Air Supply is not connected or turned on.
Connect the Air Supply and turn it on. Ensure it has the proper air pressure
(75 psi recommended).
Problem:
Solution: Power supply is not connected properly or turned on.
Verify that the power supply is connected properly (with the correct polarity)
or turn it on. Use a digital voltmeter to verify that 24 VDC is present on the
PCS PC board.
Problem:
Solution: The actuator air lines are reversed.
Check installation diagram to ensure proper connection. Connect lines to
proper ports if necessary.
Problem:
Solution: Dip Switch SW1 (Deadband adjustment) is in the Set position.
Move Dip Switch SW1 to the Normal position.
Problem:
Solution: No feedback signal from the actuator.
Verify proper connection of the feedback cable to the PCS using Figure 2. If
the connection is correct, use a digital voltmeter and verify that there is 10
VDC present across the PCS Sensor terminals A and C. If 10 VDC is not
present, there is a problem with the PCS Sensor excitation circuit and will
need repaired. If the 10 VDC is present, check to see if there is voltage
present between Sensor terminals B and C (this is the actuator feedback,
which should vary from approximately 0 VDC when the actuator is in the
zero position and to approximately 10 VDC when the actuator is positioned
near full scale). If this signal is not present, or doesn’t change when the
actuator is moved (disconnect the air supply and move by hand if necessary),
there may be a problem with the actuator. At this point, call your local
distributor or Bimba’s Technical Assistance Center for additional assistance.
Problem:
Solution: No command signal from the Main Control.
Ensure that the connections between the Main Control and the PCS are
connected according to Figure 2 (Use correct polarity). Also, verify that the
Main Control is sending a command signal. This can be accomplished with a
volt meter (for a 0-10 VDC command signal) or an ammeter (for 4-20mA or
0-20mA command signals). Check the signal on the PCS terminal.